University of Texas, Arlington NURS 5334/NURS5334:ABX Exam Complete Questions and Answers (Explained)| 100% correct 2025/26.

University of Texas, Arlington NURS 5334/NURS5334:ABX Exam Complete Questions and Answers (Explained)| 100% correct 2025/26. UT Arlington ABX Exam Complete Questions and Answers/Explained_ Updated Fall 2025. Antimicrobial Therapy: Advanced Multiple-Choice Questions Section 1: General Principles of Antimicrobial Therapy 1. A patient with a history of penicillin anaphylaxis requires treatment for a gram- negative infection. Which antibiotic is the safest alternative? o A) Cefazolin o B) Aztreonam o C) Meropenem o D) Ampicillin-sulbactam 2. A critically ill patient presents with neutropenic fever. What is the best initial empiric therapy? o A) Vancomycin o B) Cefepime o C) Clindamycin o D) Amoxicillin 3. Which of the following is NOT a factor in selecting an appropriate antimicrobial agent? o A) Route of administration o B) Minimum inhibitory concentration (MIC) o C) Patient’s age o D) The presence of viral infection Section 2: Cell Wall Synthesis Inhibitors 4. Which of the following beta-lactam antibiotics is most resistant to beta-lactamases? o A) Amoxicillin o B) Cefepime o C) Piperacillin o D) Penicillin G 5. What is the primary mechanism of resistance against methicillin in MRSA? o A) Beta-lactamase production o B) Efflux pumps o C) Altered penicillin-binding proteins (PBPs) o D) Reduced drug permeability Section 3: Protein Synthesis Inhibitors 6. Which of the following antibiotics inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit? o A) Gentamicin o B) Doxycycline o C) Azithromycin o D) Ciprofloxacin 7. Aminoglycosides should be avoided in patients with which condition due to increased toxicity risk? o A) Liver failure o B) Renal failure o C) Diabetes o D) Asthma Section 4: DNA/RNA Synthesis Inhibitors 8. Which of the following statements about fluoroquinolones is TRUE? o A) They inhibit bacterial DNA gyrase and topoisomerase IV. o B) They are recommended for treating pediatric patients. o C) They have no activity against gram-negative organisms. o D) They are primarily bacteriostatic. 9. Which fluoroquinolone is most effective against Pseudomonas aeruginosa? o A) Moxifloxacin o B) Levofloxacin o C) Ciprofloxacin o D) Nalidixic acid Section 5: Antifungal & Antiviral Agents 10. What is the mechanism of action of azole antifungals? • A) Inhibition of squalene epoxidase • B) Disruption of the fungal cell membrane • C) Inhibition of ergosterol synthesis • D) Inhibition of DNA polymerase 11. Which antiviral agent is a nucleoside analog used to treat herpes simplex virus (HSV) infections? • A) Acyclovir • B) Oseltamivir • C) Foscarnet • D) Rimantadine Section 6: Clinical Scenarios and Advanced Applications 12. A 35-year-old woman presents with a UTI caused by ESBL-producing E. coli. Which antibiotic is most appropriate? • A) Trimethoprim-sulfamethoxazole • B) Nitrofurantoin • C) Meropenem • D) Azithromycin 13. A 55-year-old male with a history of atrial fibrillation is prescribed clarithromycin for pneumonia. What potential drug interaction should be considered? • A) Warfarin metabolism inhibition • B) Increased risk of QT prolongation • C) Decreased digoxin levels • D) Induction of cytochrome P450 enzymes 14. Which antibiotic should be avoided in pregnancy due to the risk of fetal cartilage toxicity? • A) Penicillin • B) Tetracycline • C) Ciprofloxacin • D) Azithromycin Section 7: Beta-Lactam Antibiotics (Penicillins, Cephalosporins, Carbapenems, Monobactams) 15. Which of the following cephalosporins has the best CNS penetration and is used to treat bacterial meningitis? • A) Cefazolin • B) Cefotaxime • C) Cephalexin • D) Cefuroxime 16. Which of the following is a key advantage of carbapenems over other beta-lactams? • A) No risk of seizures • B) Activity against multidrug-resistant organisms, including ESBLs • C) Lower cost • D) No renal dose adjustment required 17. Which beta-lactam antibiotic is safe to use in patients with severe penicillin allergies? • A) Ceftriaxone • B) Aztreonam • C) Meropenem • D) Piperacillin Section 8: Aminoglycosides and Tetracyclines 18. Which of the following aminoglycosides is commonly used to treat tuberculosis? • A) Gentamicin • B) Tobramycin • C) Amikacin • D) Streptomycin 19. Tetracyclines should not be taken with which of the following due to decreased absorption? • A) Milk and dairy products • B) Alcohol • C) High-protein meals • D) Leafy green vegetables Section 9: Macrolides, Clindamycin, and Linezolid 20. Which macrolide is least likely to cause drug interactions via CYP450 inhibition? • A) Erythromycin • B) Clarithromycin • C) Azithromycin • D) Telithromycin 21. Clindamycin is associated with which major adverse effect? • A) Stevens-Johnson Syndrome • B) Pseudomembranous colitis • C) Ototoxicity • D) Anemia 22. Which antibiotic is a reversible MAO inhibitor and requires monitoring for serotonin syndrome? • A) Vancomycin • B) Clindamycin • C) Linezolid • D) Daptomycin Section 10: Fluoroquinolones 23. Which fluoroquinolone is best suited for treating community-acquired pneumonia? • A) Ciprofloxacin • B) Levofloxacin • C) Nalidixic acid • D) Norfloxacin 24. Which of the following is a black box warning for fluoroquinolones? • A) Hepatotoxicity • B) Tendon rupture • C) Stevens-Johnson syndrome • D) QT shortening Section 11: Antifungal and Antiviral Therapy 25. Which antifungal is a polyene that disrupts fungal cell membranes by binding ergosterol? • A) Fluconazole • B) Amphotericin B • C) Voriconazole • D) Terbinafine 26. Which antiviral drug is used as first-line therapy for CMV infections? • A) Acyclovir • B) Valacyclovir • C) Ganciclovir • D) Oseltamivir Section 12: Antimicrobial Resistance and Stewardship 27. Which of the following mechanisms contributes to vancomycin resistance in Enterococcus? • A) Beta-lactamase production • B) Altered ribosomal binding sites • C) Modification of D-Ala-D-Ala to D-Ala-D-Lac • D) Increased efflux pump activity 28. Which of the following strategies is most effective for preventing antibiotic resistance? • A) Using broad-spectrum antibiotics for all infections • B) Empiric therapy without de-escalation • C) Adherence to antimicrobial stewardship principles • D) Increasing antibiotic doses in all patients Section 13: Clinical Cases and Decision-Making 29. A 65-year-old patient with diabetes presents with necrotizing fasciitis. What is the best empiric treatment? • A) Ceftriaxone • B) Vancomycin + Piperacillin-Tazobactam • C) Azithromycin • D) Clindamycin 30. Which antibiotic is contraindicated in children due to permanent teeth discoloration? • A) Erythromycin • B) Tetracycline • C) Azithromycin • D) Trimethoprim Section 14: Advanced Clinical Cases 31. A 72-year-old male with CKD is prescribed an aminoglycoside. What adjustment is required? • A) Increase dose and shorten dosing interval • B) Decrease dose and extend dosing interval • C) No adjustment needed • D) Switch to a cephalosporin 32. Which antibiotic is best for treating Mycoplasma pneumoniae pneumonia? • A) Ceftriaxone • B) Levofloxacin • C) Azithromycin • D) Vancomycin 33. A patient receiving metronidazole should be advised to avoid which of the following? • A) Dairy products • B) Iron supplements • C) Alcohol • D) High-fat meals Section 15: Mechanisms of Action & Resistance 34. Which of the following drugs disrupts bacterial DNA by forming free radicals? • A) Metronidazole • B) Clindamycin • C) Linezolid • D) Doxycycline 35. Fluoroquinolone resistance is primarily mediated by: • A) Ribosomal mutations • B) Alterations in DNA gyrase and topoisomerase IV • C) Beta-lactamase enzymes • D) Decreased protein synthesis Section 16: Pharmacokinetics & Drug Interactions 36. Which cephalosporin does NOT require renal dose adjustment? • A) Cefazolin • B) Cefepime • C) Ceftriaxone • D) Ceftazidime 37. Which drug class has the longest post-antibiotic effect (PAE) against gram-negative bacteria? • A) Beta-lactams • B) Macrolides • C) Aminoglycosides • D) Tetracyclines Section 17: Antifungal & Antiviral Therapy 38. Which antifungal drug inhibits squalene epoxidase, blocking ergosterol synthesis? • A) Fluconazole • B) Amphotericin B • C) Terbinafine • D) Caspofungin 39. What is the most common side effect of oseltamivir? • A) Nephrotoxicity • B) Gastrointestinal upset • C) Hepatotoxicity • D) Arrhythmias Section 18: Clinical Decision-Making 40. A patient with ESBL-producing Klebsiella pneumoniae is best treated with: • A) Piperacillin-Tazobactam • B) Cefepime • C) Meropenem • D) Vancomycin 41. Which antibiotic is contraindicated in neonates due to the risk of kernicterus? • A) Vancomycin • B) Ceftriaxone • C) Erythromycin • D) Gentamicin Section 19: Miscellaneous Topics 42. Which drug is the first-line treatment for Clostridioides difficile infection? • A) Metronidazole • B) Vancomycin (oral) • C) Fidaxomicin • D) Clindamycin 43. A 65-year-old patient with atrial fibrillation is started on clarithromycin for pneumonia. What should be monitored? • A) Blood glucose levels • B) QT interval • C) Renal function • D) Platelet count 44. Which of the following antibiotics should be avoided in patients with myasthenia gravis? • A) Azithromycin • B) Gentamicin • C) Doxycycline • D) Trimethoprim 45. Which drug combination exhibits synergistic activity against Enterococcus infections? • A) Ampicillin + Gentamicin • B) Ceftriaxone + Metronidazole • C) Vancomycin + Rifampin • D) Azithromycin + Doxycycline Final Section: Comprehensive Clinical Scenarios 46. A 55-year-old diabetic patient presents with osteomyelitis. Which of the following would be the best empiric therapy? • A) Vancomycin + Cefepime • B) Clindamycin + Azithromycin • C) Amoxicillin + Metronidazole • D) Piperacillin-Tazobactam alone Answer: A) Vancomycin + Cefepime Explanation: This covers MRSA, gram-negative rods, and Pseudomonas. 47. A patient presents with fever and a history of a prosthetic heart valve. Blood cultures reveal Staphylococcus epidermidis. What is the most appropriate treatment? • A) Ceftriaxone + Azithromycin • B) Vancomycin + Rifampin + Gentamicin • C) Daptomycin + Piperacillin-Tazobactam • D) Ciprofloxacin + Metronidazole Beta-Lactam Antibiotics: Mechanism, Use, and Resistance 1. A 72-year-old male with CKD is prescribed an aminoglycoside. What adjustment is required? • A) Increase dose and shorten dosing interval • B) Decrease dose and extend dosing interval • C) No adjustment needed • D) Switch to a cephalosporin 2. Which cephalosporin has the best CNS penetration and is used for bacterial meningitis? • A) Cefazolin • B) Cefotaxime • C) Cephalexin • D) Cefuroxime 3. Which of the following is the best empiric treatment for neutropenic fever? • A) Vancomycin • B) Cefepime • C) Clindamycin • D) Amoxicillin Fluoroquinolones and DNA Synthesis Inhibitors 4. Fluoroquinolone resistance is primarily mediated by: • A) Ribosomal mutations • B) Alterations in DNA gyrase and topoisomerase IV • C) Beta-lactamase enzymes • D) Decreased protein synthesis Macrolides and Protein Synthesis Inhibitors 5. A patient receiving clarithromycin for pneumonia should be monitored for which adverse effect? • A) Hyperkalemia • B) QT prolongation • C) Acute renal failure • D) Neutropenia Vancomycin and MRSA Therapy 6. Which of the following mechanisms contributes to vancomycin resistance in Enterococcus (VRE)? • A) Beta-lactamase production • B) Altered ribosomal binding sites • C) Modification of D-Ala-D-Ala to D-Ala-D-Lac • D) Increased efflux pump activity Metronidazole and Anaerobic Infections 7. A patient receiving metronidazole should be advised to avoid: • A) Dairy products • B) Alcohol • C) Iron supplements • D) High-fat meals Empiric Therapy and Antimicrobial Stewardship 8. A patient presents with a prosthetic heart valve and blood cultures reveal Staphylococcus epidermidis. What is the most appropriate treatment? • A) Ceftriaxone + Azithromycin • B) Vancomycin + Rifampin + Gentamicin • C) Daptomycin + Piperacillin-Tazobactam • D) Ciprofloxacin + Metronidazole Beta-Lactam Antibiotics: Mechanism, Use, and Resistance 1. A 72-year-old male with CKD is prescribed an aminoglycoside. What adjustment is required? • A) Increase dose and shorten dosing interval • B) Decrease dose and extend dosing interval • C) No adjustment needed • D) Switch to a cephalosporin 2. Which cephalosporin has the best CNS penetration and is used for bacterial meningitis? • A) Cefazolin • B) Cefotaxime • C) Cephalexin • D) Cefuroxime 3. Which of the following is the best empiric treatment for neutropenic fever? • A) Vancomycin • B) Cefepime • C) Clindamycin • D) Amoxicillin Fluoroquinolones and DNA Synthesis Inhibitors 4. Fluoroquinolone resistance is primarily mediated by: • A) Ribosomal mutations • B) Alterations in DNA gyrase and topoisomerase IV • C) Beta-lactamase enzymes • D) Decreased protein synthesis Macrolides and Protein Synthesis Inhibitors 5. A patient receiving clarithromycin for pneumonia should be monitored for which adverse effect? • A) Hyperkalemia • B) QT prolongation • C) Acute renal failure • D) Neutropenia Vancomycin and MRSA Therapy 6. Which of the following mechanisms contributes to vancomycin resistance in Enterococcus (VRE)? • A) Beta-lactamase production • B) Altered ribosomal binding sites • C) Modification of D-Ala-D-Ala to D-Ala-D-Lac • D) Increased efflux pump activity Metronidazole and Anaerobic Infections 7. A patient receiving metronidazole should be advised to avoid: • A) Dairy products • B) Alcohol • C) Iron supplements • D) High-fat meals Empiric Therapy and Antimicrobial Stewardship 8. A patient presents with a prosthetic heart valve and blood cultures reveal Staphylococcus epidermidis. What is the most appropriate treatment? • A) Ceftriaxone + Azithromycin • B) Vancomycin + Rifampin + Gentamicin • C) Daptomycin + Piperacillin-Tazobactam • D) Ciprofloxacin + Metronidazole 1. A 72-year-old male with CKD is prescribed an aminoglycoside. What adjustment is required? • A) Increase dose and shorten dosing interval • B) Decrease dose and extend dosing interval • C) No adjustment needed • D) Switch to a cephalosporin 2. Which cephalosporin has the best CNS penetration and is used for bacterial meningitis? • A) Cefazolin • B) Cefotaxime • C) Cephalexin • D) Cefuroxime 3. Which of the following is the best empiric treatment for neutropenic fever? • A) Vancomycin • B) Cefepime • C) Clindamycin • D) Amoxicillin Fluoroquinolones and DNA Synthesis Inhibitors 4. Fluoroquinolone resistance is primarily mediated by: • A) Ribosomal mutations • B) Alterations in DNA gyrase and topoisomerase IV • C) Beta-lactamase enzymes • D) Decreased protein synthesis Macrolides and Protein Synthesis Inhibitors 5. A patient receiving clarithromycin for pneumonia should be monitored for which adverse effect? • A) Hyperkalemia • B) QT prolongation • C) Acute renal failure • D) Neutropenia Vancomycin and MRSA Therapy 6. Which of the following mechanisms contributes to vancomycin resistance in Enterococcus (VRE)? • A) Beta-lactamase production • B) Altered ribosomal binding sites • C) Modification of D-Ala-D-Ala to D-Ala-D-Lac • D) Increased efflux pump activity Metronidazole and Anaerobic Infections 7. A patient receiving metronidazole should be advised to avoid: • A) Dairy products • B) Alcohol • C) Iron supplements • D) High-fat meals Empiric Therapy and Antimicrobial Stewardship 8. A patient presents with a prosthetic heart valve and blood cultures reveal Staphylococcus epidermidis. What is the most appropriate treatment? • A) Ceftriaxone + Azithromycin • B) Vancomycin + Rifampin + Gentamicin • C) Daptomycin + Piperacillin-Tazobactam • D) Ciprofloxacin + Metronidazole Expanded Antimicrobial Learning Guide 1. Why are aminoglycosides given as once-daily dosing in some patients? • A) To avoid nephrotoxicity and ototoxicity • B) Because they have a long half-life • C) They are bacteriostatic at lower doses • D) To increase penetration into the CNS 2. Why should fluoroquinolones be avoided in children and pregnant women? • A) They cause hepatotoxicity • B) They interfere with fetal cardiac development • C) They inhibit bone and cartilage growth • D) They cause neural tube defects 3. Why is azithromycin preferred over erythromycin for respiratory infections? • A) It has fewer drug interactions • B) It has better gram-positive coverage • C) It has better CNS penetration • D) It is bactericidal rather than bacteriostatic 4. What is the best empiric therapy for necrotizing fasciitis? • A) Ceftriaxone • B) Clindamycin + Piperacillin-Tazobactam • C) Azithromycin • D) Ciprofloxacin 5. Why does metronidazole cause a disulfiram-like reaction with alcohol? • A) It inhibits CYP3A4 • B) It blocks dopamine reuptake • C) It inhibits aldehyde dehydrogenase • D) It induces serotonin syndrome 6. Why is rifampin not used as monotherapy for tuberculosis? • A) It has poor bioavailability • B) It induces rapid resistance • C) It causes significant nephrotoxicity • D) It does not penetrate macrophages 7. Why do carbapenems have a higher seizure risk compared to other beta- lactams? • A) They bind to NMDA receptors • B) They lower GABA levels • C) They increase dopamine release • D) They cause direct neuronal toxicity 8. Why is daptomycin ineffective for pneumonia? • A) It does not cross the blood-brain barrier • B) It is inactivated by pulmonary surfactants • C) It has poor lung penetration • D) It causes pulmonary fibrosis Antimicrobial Therapy: Case-Based Scenarios, Mechanism Diagrams, and Antibiotic Cheat Sheets 1️⃣ Case-Based Scenarios (Clinical Decision-Making) Below are realistic clinical cases designed to test application of antimicrobial knowledge, resistance patterns, and drug interactions. Case 1: Severe Sepsis with Unknown Source Scenario: A 67-year-old male with diabetes and chronic kidney disease (CKD) presents to the ER with fever (102°F), tachycardia (HR 110), and hypotension (BP 85/60). He is confused and has an elevated WBC count of 19,000/mm³. Blood cultures are pending. Question: What is the best empiric antibiotic therapy? • A) Vancomycin + Cefepime + Metronidazole • B) Ceftriaxone + Azithromycin • C) Vancomycin + Piperacillin-Tazobactam • D) Daptomycin + Linezolid Case 2: Community-Acquired Pneumonia (CAP) Scenario: A 45-year-old female presents with fever, cough, dyspnea, and right lower lobe infiltrates on chest X-ray. She was healthy prior to illness and has no recent hospitalizations. Question: What is the most appropriate outpatient treatment? • A) Levofloxacin • B) Amoxicillin-Clavulanate + Azithromycin • C) Piperacillin-Tazobactam • D) Vancomycin Case 3: Urinary Tract Infection (UTI) with ESBL-Producing E. coli Scenario: A 30-year-old pregnant woman presents with burning urination and fever. Urinalysis shows pyuria, nitrites, and leukocyte esterase. Urine culture grows ESBL-producing E. coli. Question: What is the most appropriate treatment? • A) Nitrofurantoin • B) Fosfomycin • C) Ceftriaxone • D) Meropenem 2️⃣ Antibiotic Mechanism Diagrams Below is a visual guide to the mechanisms of action of major antibiotics. ˙6 Bacterial Targets of Antibiotics Antibiotic Class Mechanism of Action Example Drugs Beta-lactams Inhibit peptidoglycan synthesis (cell wall) Penicillins, Cephalosporins, Carbapenems Glycopeptides Bind D-Ala-D-Ala to prevent cell wall synthesis Vancomycin Aminoglycosides Bind 30S ribosome, inhibiting protein synthesis Gentamicin, Amikacin Macrolides Bind 50S ribosome, inhibiting translocation Azithromycin, Clarithromycin Fluoroquinolones Inhibit DNA gyrase & Topoisomerase IV Ciprofloxacin, Levofloxacin Metronidazole Forms free radicals, damaging DNA Metronidazole Sulfonamides Inhibit folic acid synthesis Trimethoprim-Sulfamethoxazole 3️⃣ Antibiotic Cheat Sheets Quick-reference charts for choosing the right antibiotic. ▲I—* Empiric Antibiotic Guide Infection First-Line Treatment Alternatives Community-Acquired Pneumonia (CAP) Hospital-Acquired Pneumonia (HAP) Bacterial Meningitis Sepsis UTI (Uncomplicated) UTI (Complicated or ESBL) C. difficile Colitis ˙6 Resistant Bacteria and How to Treat Them Resistant Pathogen Treatment of Choice MRSA VRE (Vancomycin-Resistant Enterococcus) Pseudomonas aeruginosa ESBL-producing Enterobacteriaceae CRE (Carbapenem-Resistant Enterobacteriaceae) Case 1: A 32-Year-Old Male with Community-Acquired Pneumonia (CAP) Clinical Presentation • Patient: 32-year-old male, previously healthy • Symptoms: Cough, fever (102°F), chills, dyspnea, pleuritic chest pain • Physical Exam: o Crackles over the right lower lung o Mild respiratory distress • Labs & Imaging: o WBC count: 15,000/mm³ o Chest X-ray: Right lower lobe consolidation Question: What is the most appropriate outpatient treatment? • A) Levofloxacin • B) Azithromycin • C) Vancomycin • D) Cefepime Case 2: A 70-Year-Old Male with Hospital-Acquired Pneumonia (HAP) Clinical Presentation • Patient: 70-year-old male, recently intubated for COPD exacerbation • Symptoms: Worsening fever, productive cough, increased oxygen needs • Labs & Imaging: o WBC count: 18,500/mm³ o Chest X-ray: Bilateral infiltrates o Sputum Culture: Pseudomonas aeruginosa Question: What is the best empiric therapy? • A) Vancomycin + Cefepime • B) Levofloxacin + Clindamycin • C) Piperacillin-Tazobactam + Tobramycin • D) Meropenem Case 3: A 40-Year-Old Female with Pyelonephritis Clinical Presentation • Patient: 40-year-old female with fever, flank pain, nausea • Vitals: o Temp: 102.3°F o BP: 120/70 o HR: 95 • Urinalysis: o Leukocyte esterase: Positive o Nitrites: Positive o WBC: 100/hpf • Urine Culture: E. coli (Extended-Spectrum Beta-Lactamase [ESBL] positive) Question: What is the most appropriate treatment? • A) Nitrofurantoin • B) Ciprofloxacin • C) Meropenem • D) Amoxicillin Case 4: A 55-Year-Old Diabetic Patient with Necrotizing Fasciitis Clinical Presentation • Patient: 55-year-old male with diabetes • Symptoms: Severe pain, redness, swelling of the left leg, fever 103°F • Physical Exam: o Crepitus on palpation o Rapidly spreading purple discoloration • Labs: o WBC: 21,000/mm³ o Lactate: High • Blood Culture: Streptococcus pyogenes (GAS) Question: What is the best treatment? • A) Ceftriaxone • B) Clindamycin + Piperacillin-Tazobactam • C) Doxycycline + Metronidazole • D) Azithromycin Case 5: A 65-Year-Old Male with Prosthetic Valve Endocarditis Clinical Presentation • Patient: 65-year-old male with a mechanical heart valve • Symptoms: Fever, weight loss, night sweats • Blood Culture: Staphylococcus epidermidis • Echocardiogram: Vegetation on the aortic valve Question: What is the most appropriate treatment? • A) Ceftriaxone • B) Vancomycin + Rifampin + Gentamicin • C) Clindamycin • D) Ciprofloxacin 1. A 50-year-old man presents with fever, chills, and productive cough. Chest X- ray shows right lower lobe consolidation. Sputum culture grows Streptococcus pneumoniae. The patient has no significant past medical history. What is the best treatment? • A) Amoxicillin • B) Ciprofloxacin • C) Vancomycin • D) Piperacillin-Tazobactam 2. A 65-year-old woman with a history of diabetes and CKD presents with fever, flank pain, and dysuria. Urine culture grows ESBL-producing E. coli. What is the most appropriate treatment? • A) Nitrofurantoin • B) Ceftriaxone • C) Meropenem • D) Trimethoprim-Sulfamethoxazole 3. A 70-year-old male is admitted with hospital-acquired pneumonia (HAP). Blood cultures grow Pseudomonas aeruginosa. Which is the best antibiotic choice? • A) Vancomycin • B) Cefepime • C) Clindamycin • D) Azithromycin 4. A 30-year-old pregnant woman presents with a urinary tract infection (UTI). She has a mild penicillin allergy (rash). What is the safest treatment option? • A) Ciprofloxacin • B) Nitrofurantoin • C) Doxycycline • D) Trimethoprim-Sulfamethoxazole 5. A 55-year-old male with cirrhosis develops spontaneous bacterial peritonitis (SBP). What is the most appropriate first-line antibiotic? • A) Piperacillin-Tazobactam • B) Ceftriaxone • C) Linezolid • D) Azithromycin 6. A 25-year-old man presents with a painless genital ulcer. He had unprotected intercourse 3 weeks ago. Blood tests confirm Treponema pallidum. What is the best treatment? • A) Ceftriaxone • B) Benzathine Penicillin G • C) Doxycycline • D) Azithromycin . 7. A 60-year-old diabetic male with an infected foot ulcer grows MRSA on culture. What is the best treatment? • A) Vancomycin • B) Cefazolin • C) Ciprofloxacin • D) Clindamycin Key Takeaways ⬛⬛ Amoxicillin is first-line for outpatient CAP caused by S. pneumoniae. ⬛ Carbapenems (Meropenem) are the gold standard for ESBL-producing bacteria. ⬛ Cefepime is used for hospital-acquired pneumonia with Pseudomonas coverage. ⬛ Nitrofurantoin is safe for uncomplicated UTIs in pregnancy. ⬛ Vancomycin is first-line for MRSA infections. ⬛ Benzathine Penicillin G is the treatment of choice for syphilis.